Help - broken speakers.

I like to listen to music on YouTube on my Rpi4 with Raspbian. It uses a 5-year-old BenQ monitor, and the audio signal is sent out on the HDMI cable. This morning, watching Rick’s daily Advent Calendar videos, I noticed that there was no sound. I could just about hear something if I plugged in the audio jack to its 35mm socket and stuck the bud in my ear. I have checked that /boot/config.txt has the right mantras, and am reluctantly driven to the conclusion that the speakers in the monitor are no longer functioning. I have had 5 years of service from the monitor, and buying a similar one would cost about £90 – the price has not changed. But I wondered if I could restore the sound more cheaply, by buying a device that could be connected via the audio jack. I know nothing about hi-fi, speakers, or how music is produced digitally. There is not much room on my desk for more hardware – speakers concealed in the monitor is the ideal arrangement for me – but if it were cheap enough, and I knew what was available, I would consider it. Can anybody more expert in such matters advise me?

If your jack plugs are 1/8", it’s not surprising they don’t work. The sockets are for 3.5mm plugs, and 1/8" ones will be so loose the contact will be unreliable. 1/8" is only 3.175mm.

1/8" is only 3.175mm.

And 35mm is a bit on the large size! That must be a typo!

Could US inches be a bit bigger, like their gallons?

That must be a typo!

I wrote 3.5mm. I haven’t edited it, it was always 3.5mm.

Could US inches be a bit bigger, like their gallons?

No, their inches are exactly the same as Imperial ones; but their gallons are smaller, not bigger.

Some got spilled when the Mayflower hit choppy waters.

I wrote 3.5mm. I haven’t edited it, it was always 3.5mm.

Of course: It was Gavin who made that typo:

I could just about hear something if I plugged in the audio jack to its 35mm socket and stuck the bud in my ear.

It was Gavin who made that typo

Ah, okay. Missed that! :-)

My interest piqued, I just pulled the jack of my Sony headphones, imported from Japan, out of the back of my Mac Mini, since I have a micrometer handy.

It’s exactly 3.5mm in diameter, not 3.35, nor 3.175 – EXACTLY 3.5, as near as my micrometer can tell. That is, to the nearest 0.005mm.

I very much doubt that this is unusual.

Tight? Well, it’s not loose, certainly. It’s quite snug. It’s clearly exactly the right diameter for the jack socket on my Mac, imported from the USA (but for all I know, made in China). Which is not very surprising, since the specification is 3.5mm…

It’s a late 2014 Apple Mac Mini.

Sorry about the wrong measurements for the earbud jack. It is precisely as long as my thumbnail. The earbud came with my ARMBook. What about a small portable Bluetooth speaker? Could that adequately replace the speaker in the now silent monitor? Audio technology is yet another area of life, along with photography, finance, law and genealogy, that I have been happy to leave to others; hence the naive questions.

I use a small Bluetooth speaker to connect to 3.5mm audio occasionally. Fine for what it’s needed for.

Thanks. I have ordered a device called NUBWO, at a cost of £10.98. At that price I can afford to experiment. So far I have not made trial of the Raspberry Pi’s Bluetooth capabilities.

Probably within spec, then. I don’t know what the tolerance is. Unlikely to be so loose that they’re the problem – whereas 1/8" very likely would be, especially in a socket that’s had a 3.5mm one in it a lot.

The tolerance to allow a 3.35mm jack in a 3.5mm socket seems reasonable. You could design a socket to accept anything from 1/8" to 3.5mm but it cost a bit more because you’d need a better grade of spring material. You’re talking fractions of penny (or cent) not for the material (trivial difference) but for the forming process. Not a big deal, but even those tiny amounts add up and engineers wouldn’t do it if they didn’t have to.

I wonder whether there used to be two different standards, 1/8" probably USA, 3.5mm probably the rest of the world.

(My first degree was Mechanical Engineering…)

1/4" really is exactly the same as 6.35mm 8~) and was of course a standard that originated in the USA (or perhaps the UK…)

Having measured many a such jack, to find one that is exactly 3.5 is a rare ocasion. Though I would bet also a bit of a tight fit.

Just routinely precise. Here we would regard items that didn’t match the stated dimensions as “probably cheap foreign rubbish”
Now that might be a tad xenophobic but it’s largely true.

An old story from decades ago:
A large US tool manufacturer sent samples of their new product
“The smallest, hardest, most precise drill in the world” to have one UK firm send it back to them with a hole drilled precisely up the middle…

one UK firm send it back to them with a hole drilled precisely up the middle

I did a (programming) contract in the mid-1970s for the British company (the 600 Group) who did that 8~). They did actually cheat: the hole was drilled with an electron beam machine…

A hole is a hole.

A hole is a hole.

A receptacle a receptacle!

We look forward to your contribution!

If the output socket on the monitor is to drive a conventional pair of (analog stereo) headphones it should also drive an analog input to a speaker that has iit’s own internal amplifier. I assume that in this context ‘bluetooth’ would simply be an intermediate ‘get from A to B’ to allow a wireless link. The socket probably wouldn’t have enough wellie (technical term :-) ) to drive a plain loudspeaker that didn’t have an amplifier.

Does the monitor have an optical output for audio? If so, that and a digital link via a DAC would work better I suspect. Assuming you want quality rather than width. 8-]

Of course, if people had finally by now got round to having USB Audio working on most RO hardware, that would be a better quality and simpler solution. :-)

Alas, we’re still waiting for that…

My monitor always baffled me when I first got it – it had a speaker volume setting in the OSD, but no apparent speaker – there were none. It also showed up in Windows/Linux as a sound output device. I realised only a few months back that it had an audio jack tucked away that when plugged into external speakers played audio sent over HDMI.